A method for calibrating a mixer, an apparatus using the calibrated mixer, and a method for using the apparatus to calibrate another mixer are disclosed. The method includes coupling a first RF signal characterized by a first timezero phase and a first RF frequency to the RF signal input. The method includes (a) coupling a first LO signal characterized by a first LO frequency and a first LO timezero phase to the LO signal input terminal; (b) determining an IF tone timezero phase of a tone from the IF signal output corresponding to the first LO signal; and (c) determining a first after LO signal path timezero phase from the IF tone and first LO timezero phase. Steps (a), (b), and (c) are repeated for second and third LO signals. An LO phase change as a function of frequency introduced by the LO signal path is then determined.